Manufacture of wires and tapes for loading telephone conductors



An alloy composed of Patented Aug. 6, 1929.

UNITED STATES PATENT OFFICE.

WILLOUGHBY STATHAM SMITH, O]? NEWTON POPPLEFORD, AND HENRY JOSEPH GABNETT, OF SEVENOAKS, ENGLAND.

IANUFACTURE OF WIRES AND TAPES FOR LOADING TELEPHONE CONDUCTORS.

Io Drawing. Application filed February 17, 1926, Serial No. 88,952, and in Great Britain February 17, 1925.

This invention relates to the manufacture 5 able for the purpose are composed o nickel,

copper and iron and free from carbon, in which the nickel ranges from 30% to 33% of the whole, the iron from 58% to 65% of the Whole, and the copper from 2% to 6% of the 1 whole.-

As a result of our experiments we find that these alloys have valuable properties.

Example.

Per cent.

' Nickel 33 Iron 65 Copper 2 has an initial permeability of 1000 and a specific resistance of 80 michroms per cm".

Forcertain purposes, such as for increasing the electrical resistance of the alloy, we

introduced an additional element, which may be chromium, vanadium, tungsten, molybdenum, silicon, aluminum or titanium; the

percentage of the added element should not Nickel 33 35 Iron 64.5

Copper 2 Vanadium 0.-5

when suitably annealed had an initial per o meability of 600 and a specific resistance of 85 michroms per cm.

When the vanadium is increased to 0.75% the specific resistance is 89 michroms per cm and the initial permeability 400.

An alloy of the following composition Per cent. Nickel 33 Iron 63. 5 Copper 2. 5 Chromium 1.0

gave an initial permeability of 610 and a specific resistance of 90 michroms per cm.

In order to develop the desired magnetic properties the alloys require suitable heat treatment. This consists of annealing in an atmosphere of nitrogen at a temperature of 850 930 C. followed by cooling in the same inert gas.

Small amounts of mag'anese not exceeding 1% may be added to promote forgeability and ductility.

What we claim is 1. Carbon free wires or tapes for loading magnetic conductors'comprising nickel 30% to 33% of the whole, iron 58% to 65% of the whole, and copper 2% to 6% of the whole.

2. Carbon free wires or tapes for loading magnetic conductors comprising nickel 30% to 33% of the whole, iron 58% to 65% of the whole, copper 2% to 6% of the whole, and a fourth element not exceeding 3% of the whole and which is adapted to increase the electrical resistance, the combined percentage of the copper and said added element not exceeding 7% of the whole.

3. Carbon free wires or tapes for'loading magnetic conductors comprising nickel 33% iron 63.5% copper 2.5%, and vanadium 0.5%. v

In testimony that-we claim the foregoing as our invention, we have signed our names this fifth day of February, 1926.

WiLLoUoHBY STATHAM SMITH. HENRY JOSEPH GARNETT. 

